Riparian refers to anything located on or related to the banks of a river, such as riparian wildlife.
The roots of the word riparian are related to rivers, and that's exactly what this word refers to: riparian things have something to do with the banks of a river or stream. A person selling fishing lures by the river has a riparian business. A frog that lives by the river bank is a riparian critter. A riparian state is located alongside a river.